Non-invasive imaging technologies allow images of the internal structures of a subject (e.g., a patient or object) to be obtained without performing an invasive procedure on the patient or object. Non-invasive imaging systems may operate based on the transmission and detection of radiation through or from a subject of interest (e.g., a patient or article of manufacture). For example, X-ray based imaging techniques (such as mammography, fluoroscopy, computed tomography (CT), and so forth) typically utilize an external source of X-ray radiation that transmits X-rays through a subject and onto a detector disposed opposite the X-ray source that detects the X-rays transmitted through the subject.
In such radiation-based imaging approaches, the radiation detector is an integral part of the imaging process and allows the acquisition of the radiation transmission data used to generate the images or data of interest. In certain radiation detection schemes, the radiation may be detected by use of a scintillating material that converts the higher energy radiation (e.g., X-rays) to optical light photons (e.g., visible light), which can then be detected by photodetector devices, such as photodiodes.
In certain implementations, it may be useful to obtain radiation transmission information for different wavelengths or spectra of the radiation. In particular, the differential transmission of radiation at different energies may provide useful information about the composition of the materials through which the radiation is passing. In such implementations, two or more energy levels or spectra of radiation may be used to obtain this differential transmission information, with separate images acquired at each energy. In conventional approaches, multi-energy images are normally taken by repeating the same procedure, which is exposure and subsequent readout for each X-ray energy, due to: (1) slow switching speed between each energy and (2) the image sensor employed can store only one image at a time. However, existing detection schemes may prove limiting in such multi-energy applications. For example, in instances where the imaging context is rapidly changing or otherwise dynamic (e.g., in cardiac applications, in interventional implementations, or where a dissipating contrast agent is employed), the speed at which sequential images at different energies are acquired may be insufficient due to the speed at which the detector may be read out and readied for subsequent image acquisition.